Length / height for age
Shows how length or height compares with children of the same age and sex.
Little Steps
Parent tools
Quick calculators and trustworthy reference guides. Calculator entries stay in your browser and are not sent to a server.
Baby age calculator
Calculate age in years, months and days from a birth date.
Due date calculator
Estimate a due date from the first day of the last menstrual period.
Growth-chart explainer
Understand percentiles and what matters more than a single point.
Official vaccination links
Go directly to current schedules from public-health authorities.
Sleep reference
Age-based daily sleep ranges, including naps where applicable.
General educational information only. For urgent symptoms or individual medical advice, contact a qualified health professional.
Baby age calculator
Due date calculator
Estimate only. Clinical dating may differ.
Growth-chart explainer
Growth charts compare a child's measurements with a reference population. A percentile is not a grade: the pattern over time matters more than one isolated number.
Weight for age
Shows weight relative to age. It does not by itself describe body proportion.
Weight for length / height
Helps assess weight in relation to body length or height.
Head circumference
Often tracked in infancy and early childhood as one part of overall growth.
WHO publishes Child Growth Standards for children from birth to age 5, including percentile and z-score charts.
WHO Child Growth Standards ↗Official vaccination links
Vaccination schedules depend on country, age, health history and previous doses. Use the official schedule for where your child receives care.
United States — CDC
Current child and adolescent immunization schedule.
Taiwan — Taiwan CDC
Current routine childhood vaccination schedule.
Japan — MHLW
Official vaccine information from Japan's Ministry of Health, Labour and Welfare.
If a child is behind schedule, has a medical condition, or had a previous vaccine reaction, ask a clinician which catch-up schedule applies.
Sleep reference
Approximate recommended sleep in a 24-hour period. Individual needs vary, and naps are included where noted.
0–3 months
14–17 hours/day
Sleep patterns vary widely in early infancy.
4–12 months
12–16 hours/day
Including naps.
1–2 years
11–14 hours/day
Including naps.
3–5 years
10–13 hours/day
Including naps.
6–12 years
9–12 hours/day
These ranges are general guidance, not a target every child must hit exactly. Persistent snoring, breathing pauses, severe daytime sleepiness or ongoing sleep difficulties deserve medical assessment.
CDC sleep guidance ↗